The invention relates to the trucking industry and, more particularly, to the rewinding of load straps of the type used to secure loads on flat bed trucks back onto the winch.
Typical flat bed trucks employ a number of load straps each coiled onto a winch that are used for securing loads on the flat bed trailer during travel. For instance, a flat bed trailer may have as many as twelve straps each measuring twenty-seven feet in length and coiled onto winch drums positioned along both sides of the flat bed. After these load straps have been unwound and used to secure a load for delivery, they must all be rewound again in order to secure the vehicle for travel. For most drivers, the only way to rewind the load straps is by grasping the round winch drum with one""s hand and to twist it using wrist motion. This is exceedingly slow and often causes injury to the forearm over time. The winches are typically mounted directly below and close to the edge of the trailer, often on a track so they can be slid lengthwise along the trailer to optimally position the strap. The mounting of the winch close to the edge of the trailer often leaves very little radial clearance around the winch drum and the positioning along, the trailer may place it very close to another winch or part of the trailer, restricting access directly in front of the axial opening of the winch drum.
There are a variety of tightening bars on the market that are used to tighten winch straps around a load, but these are slow and impractical for rewinding loose straps. The tightening bars must be repeatedly removed and re-inserted for each partial revolution of the winch drum.
For example, U.S. Pat. No. 5,975,454 to Potter (1998) discloses a strap rewinding device that winds up a strap onto a coil. However, the strap has to be fully removed from the load winch and truck before doing so (as shown in FIGS. 6 and 7), and the rewinding device must be stored separately from the winch. This causes inconvenience and makes the device impracticable for the above-described application.
U.S. Pat. No. 4,900,203 to Pope (1988) discloses a winch with a short bar passing through the winch drum to wind the strap. This approach is too slow because one cannot achieve more than one-quarter to one-half turn per bar insertion due to the presence of the trailer edge close to the winch drum. Moreover, the winch of Pope""s invention requires use of a specific winch that is not widely used in the today""s trucking industry.
U.S. Pat. No. 4,266,740 to Ramos (1980), U.S. Pat. No. 3,954,226 to Pickering (1974), U.S. Pat. No. 4,390,141 to Webster (1981), U.S. Pat. No. 4,311,288 to Gallaund (1980), and U.S. Pat. No. 5,961,061 to Stanley (1998) all disclose winding devices including a crank to wind the strap into a coil, and all require removal of the strap from the winch used to hold the load so that the strap can be rewound onto a separate device. As with Potter ""454 supra, drivers elect to wind the straps faster by grasping the extended portion of the winch drum and turning the winch drum using wrist motion.
It would be greatly advantageous to provide a load strap rewinding device that assists drivers in winding load straps back onto the very winches that they were uncoiled from.
It is, therefore, an object of the present invention to provide a truck strap rewinding device for the rewinding of load straps back onto their respective winches.
It is another object to accomplish the foregoing without need for a separate rewinding winch, and to assure rapid and safe storage of the load straps on the very same winches that are used to hold the straps under load. This would eliminate the need for separate rewinding coils as in the prior art, as well as the need for extra storage space to stow the separate coils between uses.
It is another object to provide a load strap rewinding device that saves several minutes per load thus increasing a driver""s productivity
It is still another object to provide a load strap rewinding device that operates by physical hand and arm motions that are more natural and easier than twisting the winch drum by hand, thereby saving considerable physical effort and wear and tear on the driver.
It is another object to encourage drivers to use extra load strap(s) thereby improving the safety factor of securing that load.
It is another object to provide a rewinding device that can be used on most all flat bed trailer winches currently in common use. This way, when drivers switch trailers the rewinding devices may be retrofit to their new truck.
It is another object to provide a device that will remain securely attached to the winch drum until willfully released by the driver. If the operator wishes to let go of the winding device to tighten or untangle the strap during the rewinding process, he should be able to do so without fear of the device falling on the ground. Even if the driver should forget the device and drive off with it still attached, the device should stay attached and not fall out on the way.
It is another object to employ a rewinding device with a flexible joint to apply rotation to the winch drum to avoid hitting the driver""s knuckles on the trailer edge and/or accessing a winch positioned close to an obstruction .
According to the present invention, the above-described and other objects are accomplished by providing a device for rewinding load straps onto a winch drum of a conventional load strap winch assembly. The rewinding device generally includes a spindle member adapted for axial insertion inside the hollow of the existing winch drum (of the load strap winch assembly). The spindle includes a locking member such as a detent pin that is adapted for engagement with the winch drum once the spindle member is inserted fully therein.
In addition, a spindle driver such as a hand crank or motor drive is coupled to the spindle for the purpose of applying rotational motion to the winch drum via the spindle.
The detent pin is adapted for radial outward movement to engage the winch drum, thereby causing the winch drum to rotate simultaneously with the spindle when rotational motion is applied by the hand crank/motor drive.
The detent pin is spring loaded and may be formed as a unitary member having a section of smaller diameter and a section of larger diameter, and a bore hole formed centrally along a major axis from the end of the larger diameter section almost to the end of the smaller diameter section. An extension spring may be seated in the bore hole. The extension spring biases the detent pin against the termination of the spindle hole and causes the detent pin to extend sufficiently to engage a winch bar hole on a winch drum when the spindle is inserted within the hollow of said winch drum. The detent pin is secured within the spindle by a retaining collar sized with an inner diameter to fit over the smaller section of the engagement pin, and an outer diameter to fit tightly in the spindle hole. The hand crank/motor drive may be connected directly to the spindle or through a flexible joint, and the motor drive may additionally be coupled through a right-angle drive gear.